This invention relates to multiple-needle tufting machine, and more particularly to a knife holder module for a multiple-needle cut pile tufting machine.
Conventionally, the knives utilized in multiple-needle tufting machines for cooperation with looper hooks in order to seize, hold and cut yarns delivered to the looper hooks by the needles, have been supported in individual knife blocks, which are open on the sides and include tracks or guideways for engaging the opposite edge of each knife. Each knife block is provided wwith a rearward projecting cylindrical stud or rod which is adapted to be rotatably adjustably received in a corresponding hole in a knife bar. This structure permits the knifes to be set at the desired tension angles relative to the looper hooks. The holes in the knife bars are disposed at angles to the transverse dimension of the knife bar, which are equal to the pitch angle of the knife blades relative to the looper hooks. Each knife is secured in its knife block by threaded set screws, threadedly received within the knife block for movement toward and away from direct engagement with the edge of each knife.
Other prior art knife holders include knife blocks capable of supporting multiple numbers of knives, such as two or three knives. Furthermore, in some knife blocks, one set screw may be utilized to secure two knife blades, instead of one.
Examples of typical knife holders for multiple needle cut pile tufting machines are shown in the following U.S. Pat. Nos.: 3,277,852, Card, Oct. 11, 1966; 4,003,321, Card, Jan. 18, 1977; 4,067,270, Short Jan. 10, 1978.